Coil and magnet mounting structure for an electromagnetically operated device



MARIEN COIL AND MAGNET MOUNTING STRUCTURE FOR AN N E R 1.. O O 2 6 m M 4 M w m MUM- m a. 5 H 2 w 2 6 6 KW? m T 5 8 8 9 8 E 1 8 y w 4 N 3 r v Q m l 8 i m m 0 mm m K m O WM 0 m l m -H 5 8 H w I Y,

ELECTROMAGNETICALLY OPERATED DEVICE Filed Sept. 12, 1968 Aug. 25, 1970 FIG.3

United States Patent Oflice 3,525,961 Patented Aug. 25, 1970 .COIL AND MAGNET MOUNTING STRUCTURE F(F);R AN ELECTROMAGNETICALLY OPERATED D VICE Kenneth J. Marien, Wauwatosa, Wis., assignor to Square D Company, Park Ridge, Mich., a corporation of Michigan Filed Sept. 12, 1968, Ser. No. 759,351 Int. Cl. H01h 45/02 U.S. Cl. 335-202 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electromagnetically operated devices and is more particularly concerned with an improved coil structure and mounting for a stationary magnet part, an armature and the coil in an electromagnetical- 1y operated device.

Electromagnetically operated devices, such as switches and the like, of the gravity drop-out type, conventionally include a base which is secured on a mounting panel and which provides a support for the switching contacts and an electromagnet which operates the switch contacts. As a large number of switching devices may be mounted on'a single panel, space requirements dictate that the size of the individual devices be as small as practicable without sacrificing their switching reliability and operational life. To accommodate the minimal size requirements of the devices, the magnet structures used therein tend to generate excessive heat when the devices are energized for long periods of time. In some devices the heat gen-' erated by the magnets is dissipated by mounting the magnet structures on bases which are made of die cast metal. Another requirement which the devices are required to satisfy is that the magnet coil must be readily removable for service or replacement purposes. In many prior art devices elaborate structures are used to satisfy this requirement. In the device according to the present invention, the manipulation of a pair of readily accessible screws will permit replacement of the entire magnet structure or the magnet coil, as desired. Additionally, one of the problems encountered in ele'ctromagnetically operated devices is the shock accompanying the energization of the magnet istransmitted to the contacts of the demensional variations in the coils without sacrificing the ease with which the coil may be removed and replaced from the structure and permits the energization of the coil to be visibly indicated.

It is an object of the present invention to provide an electromagnetically operated device, such as a relay, with a novel structure which will permit the electromagnet including the magnet coil to be readily removed and replaced and which will minimize the transmission of the shock accompanying the operation of the electromagnet to the switching contacts of the device.

Another object is to provide an electromagnetically operated switching device, such as a relay, with a die cast base which will dissipate the heat generated within the electromagnet, will position a shock absorbing structure to minimize transmission of shock forces to the switching contacts of the device when the electromagnet is energized, and which will position the electromagnet so the coil and other components of the electromagnet may be readily removed and installed upon manipulation of a pair of readily accessible screws.

An additional object is to provide a novel connection between the armature and the base of the device which will permit the electromagnet of the device to "be readily removed and installed on a base of the device.

A further object is to provide a novel connection between the armature and the base of an electromagnetically operated device which will permit the electromagnet of the device to be readily removed and installed on the base of the device and to provide the electromagnet with a novel coil structure that includes a molded body which will permit the coil to be secured to the base by a pair of readily accessible screws and includes a cavity having an opening which is easily visible from the front of the device when the device is mounted on a panel so an indicating lamp within the cavity may be easily observed through a transparent cover for the opening to indicate the operating condition of the device.

Further objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawing illustrating a preferred embodiment, in which:

. drawings, includes a base 12, preferably formed as a vices and causes the contacts to bounce and thus rea cording to the present invention is the use of an encapsulated coil. While encapsulated coils are well known, and are frequently used in devices of the type to which this invention relates, the novel electromagnet as used in the device according, to the present invention includes a structure which positions the'coil to compensate for diunitary part of die cast metal material to have a set of openings 14 for mounting the device on a vertical panel, not shown, with an electromagnet assembly 20 positioned at thelower vertical portion of the base 12. The opening 14 at the top of the base 12 is an inverted key hole-shaped opening and the pair of openings 14 at the bottom of the base are slots having exposed ends at the bottom edge of the base 12.

Secured at the top portion of the base 12 is an insulating support 16 carrying spaced pairs of stationary contacts.

The respective pairs of stationary contacts, not shown, are located to be bridged by movable contacts, also not shown, which are resiliently supported by springs on a movable contact carrier 18 which is biased downwardly by a spring 22. The srtucture of the support 16, the stationary contacts, the movable contacts, the movable contact carrier 18 and the spring 22 is more fully disclosed and described in an application for U.S. Pat. Ser. No.

' 759,350, which is concurrently filed herewith and has been assigned by the inventors Erik J. Nielsen and Allin W. Schubring to the assignee of the present invention.

The base 12 is symmetrical about a vertical centerline 24 and includes a pair of supporting surfaces 26 as are provided by a pair of raised walls 28 which define a socket 30. Extending forwardly of the surfaces 26 at the upper portion of the socket 30 are a pair of posts 32. The posts 32 have surfaces 34 that face one another on opposite sides of the socket 30. The posts are interconnected by a wall 36 which forms the upper wall of the socket 30 and have free ends 38 that are forwardly spaced from the supporting surfaces 26. Additionally, the post 32 each have a surface 40 extending vertically from the supporting surfaces 26 and a slot 42 in the surfaces 34 which ex tends in a common plane substantially the entire length of the posts 32 to their respective free ends 38. Extending inwardly at the lower portions of the supporting surfaces 26 in each of the walls 28 are rectangularly shaped sockets 44, and extending upwardly of the wall 36 is a projection 46. The projection 46 together with a threaded opening 48 are provided to secure the insulating support 16 to the base 12.

The electromagnet assembly includes a magnet coil 50, a stationary magnet pole 52, a magnet armature 54, and a means including a plate member 56 and a shock pad 58 as well as screws 60 for maintaining the electromagnet assembly 20 on the base 12 and absorbing shock accompanying movement of the armature 54 when the magnet coil 50 is energized and deenergized.

The magnet coil 50 includes a molded body 62 as may be formed in a manner well known to those skilled in the art to provide an encapsulated coil structure. The molded body 62 has a rear wall 64 positioned on the supporting surfaces 26 to bridge the socket 30 to provide a space 66 between the rear wall 64 and the bottom wall 68 of the socket 30. The molded body also has an upper wall 70 having portions 72 positioned adjacent the surfaces 40 and portions 74 overhanging the free ends 38 so the wall portions 74 are aligned with upper surfaces 76 of the posts 32. Extending through the molded body are a pair of spaced bores 78 which are aligned with a pair of threaded openings 80 extending from the free ends 38 in the posts 32. The bores 78 and the threaded openings 80 accept the screws 60 and thereby secure the molded body 62 on the base 12. Extending between the upper wall 70 and a lower wall 82 in the molded body 62 are a pair of bores 84 and 86. The bores are rectangular in cross-section and extend parallel to the base 12 with the bore 84 being adjacetn the rear wall 64 and the bore 86 being adjacetn a front wall 88 of the molded body 62. One manner in which the magnet coil 50 may be formed is illustraetd by FIG. 3, wherein the molded body is basically formed as a shell providing a space 90 around an opening 92 in the wall 70. The opening 92 forms one end of the bore 84 when a coil winding .94 is inserted into the space 90. The coil winding 94 may be wound on a suitable molded bobbin which provide the'remainder of the bore 84 when the bobbin which has a central bore corresponding inshape to the opening 92 is properly positioned in the space 90 with the coil winding 94 surrounding the bore 84 and the ends of the coil winding passing adjacent the bore 86 to conections with portions 96 of terminal members, as will be later described. After the coil winding 94 has been inserted in the space 90 and the ends of the winding have been connected to the terminal portions 96, the shell-like member provided by the molded body 62 is filled with a suitable encapsulating material, such as an epoxy resin, to thereby complete the molded coil body. The molded body 62 also has an opening 98 in the front wall 88 extending into a cavity 100 that is located between the front wall 88 and the bore 86. Positioned in the front wall 88 are a pair of spaced terminal members 102 each having the portion 96 formed thereon to which the ends of the coil winding 94 are connected and portions 104 extending into the cavity 100.

cating lamp 108 and the resistor 110 each have their respective terminal ends connected to the terminal portions 104, so that the resistor 110 will act as'a surge suppressor for the coil winding 94 and the indicating lamp 108 will be illuminated when the 'coil'winding 94 is energized. Thus whenever the coil winding 94 is energized, the illumination of lamp 108 will be visible through the cover 106 and if a trademark is included thereon, the trademark of the manufacturer of the device will be illuminated. As shown, the cover106 is secured on the molded body 62 by a removable screw 112 which" preferably is of the self tapping type and threaded 1nto a properly located opening in the molded body 62.

The stationary magnet part 52 includes a stack of E-shaped magnet iron parts which are laminated upon each other and tightly held assembled by rivets 114. The magnet pole 52 has a pair ofarms 116 extending from extending from a central portion of the body portion opposite ends of a body portion 118 with a central leg 120 118. The arms 116 are spaced on opposite sides of the central leg 120 and provide flat pole faces 122 wherein shading coils 124 are secured.

The armature 54 includes a stack of E-shapedmagnet iron parts which are laminated upon each other andtightly held assembled by rivets 126. The armature 154 has a pair of arms 128 extending from opposite ends of a body portion 130 with a central leg 132 extending from a central portion of the body portion 130. The arms 128 are spaced on opposite sides of the central leg 132 and provide fiat pole faces 134 which engage the pole faces 122 when the armature 54 and the magnet pole 52 are assembled with the coil 50 while a pole face 135 onthe central leg 120 is spaced from a pole face 136 on the leg 132 to provide an air gap for the electromagnet assembly 20. The armature 54 also includes a pair of spaced arms 138 which project beyond the pole face 136. The arms 138 are provided by a U-shaped member 140 which has a bight portion surrounding the body portion 130 and is held assembled by a U-shaped spring member 142 having arms hooked upon the ends of a pin 146 that extends through suitably located openings in the arms of the member 142, the arms 138 and the body portion 130. The arms 138 have slots 148 which provide clearance for the rivets 114 and extend to pro-"' vide notches 150 at the free ends of the arms 138 which are external of the body portion 118 when the armature 54 and magnet pole 52 are assembly with the coil 50. The notches 150 in each of the arms 138 have a length at least equal to the desired extent of travel of the armature 54 in the electromagnet assembly 20. 1

When the armature 54 and the magnet pole 52 are as sembled with the coil 50, the central legs 120 and 132 are inserted into the bore 84 with the body'portion. 118 positioned adjacent the upper wall 70 and the body portion 130 positioned at the lower wall 82. Whent-he armature 54, the magnet pole 52 and coil are thus assembled, one of the arms 116 and 128 of the magnet pole 52 and the armature 54 will extend in the bore 86 and the. other of the pair of arms 116 and 128 will be positioned external of the molded body 62 adjacent the rear wall 64. Also the arms 138 will present'the notches 150 external of the body portion 118 at the wall 70 end of the molded body 62.

The plate member 56 has a pair of edges 151 spacedto be received in the slots 42 and has a pairof spaced elon" gated openings 152 therein and the shock pad .58 is suitably secured to a face of the plate member 56. The openings 152 have a width and are spaced from each other to provide ample clearance with the ends of the arms 138 providing the notches 150. The length of the pair of openings 152 and the distance between the forward edge 154 of the openings 152 and the forward edge 156 of the plate member 56 is less than the distance between the roots 158 of the notches 150 and a rear portion 159 of the portion of wall 70 that rests on the free ends 38 of the posts 32. Thus the plate member 56 and the shock pad 58 may be readily positioned on the arms 138 byrnoving the laminated plate member 56 and shock pad 58 into .a position wherein the pair of openings 152 are received in the notches 150 and the shock pad 58 is positioned between the plate member 56 and the body portion 118 with the plate member 56 preventing separation of the magnet pole 52 and the armature 54 from their positions in the bores 84 and 86 of the magnet coil 50.

The electromagnet assembly 20 may be readily installed on the base 12 by inserting the edges 151 in the slots 42 andmoving the electromagnet assembly 20 toward the base 12 to a position wherein the rear wall 64 rests upon the support surfaces 26, one of the pair of arms 116 and 128 of the magnet pole 52 and the armature 54 are received in the space 66, the portion 159 of the upper wall 70 rests on the free ends 38, while the wall portion 72 is adjacent the surfaces 40 and the lower wall 82 is engaged by leaf-like spring members 160 which have one end secured in the pair of sockets 44. The springs function is to compensate the mounting for the coil body 62 for dimensional variation that occurs during manufacture of the components of the electromagnetic device 10. The electromagnet assembly is secured in position on the base 12 when the screws 60 are inserted through the bores78 and threaded into the openings 80. When the electromagnet assembly 20 is thus secured in position on the base 12, the free end edges 162 of the arms 138 will engage a metal wear plate 164 that is secured on the movable contact carrier 18.

The electromagnet assembly 20 may be readily removed from the base 12 by unthreading the pair of fastening screws 60 from the threaded openings 80 so that the electromagnet assembly 20, including the plate member 56, the screws 60, the magnet pole 52, the armature 54 and the coil 50 may be removed as a unit. When the electromagnet assembly 20 is thus removed, the coil 50 or any of the magnet parts may be readily replaced or inspected and re-installed on the base 12 in the manner previously described. The removal and insertion of the electromagnet assembly 20 is facilitated by the presence of the metal plate member 56 which slides with minimum friction across the metal base 12 and the absence of a connection-free end edge 162 on the armature 54 and the wear plate 164 on the movable contact carrier 18.

When the switch is mounted on the vertical panel and the electromagnet assembly is de-energized, the movable contact carrier 18 will be urged downwardly by the spring 22 to a limiting position wherein the top edges 166 of the notches rest on the plate 56. When the coil 50 is energized, the armature 54, which is attracted by the magnet part 52, moves the movable contact carrier 18 upwardly against the force of spring 22 and causes the pole faces 134 to engage the pole faces 122 with a firm seating engagement. The firm engagement between the pole faces 134- and 122 is aided by the slightly movable connection provided between the U-shaped member 140 and the armature 54. The shock accompanying the engagement between the armature 54 and the magnet pole 52 is transmitted by the body portion 118 to the shock pad 58. The shock pad 58 is formed of a polyurethane material which is compounded in a manner well known to those skilled in the art to possess shock absorbing power and vibration dampening characteristics. As is well known to a polymer chemist, polyurethane material is a polymeric material resulting from the condensation polymerization of diisocyanates and polyols, and thus is particularly suited to absorb the shock accompanying the energization of the electromagnet so as to minimize the phenomena known as contact bounce of the switch.

When the electromagnet assembly 20 is de-energized, the magnetic attraction between the armature 54 and the magnet pole 52 ceases and the armature 54 is moved downwardly by gravity and the force supplied by the spring 22 to the de-energized position wherein the top edges 166 engage the plate member 56. The shock ac companying the movement of the armature 52 to its de-energized position is absorbed by the shock pad 58 and the spring members 160. The spring members are arranged to constantly urge the coil 50 and the magnet pole 52 upwardly. Further, the springs 160 and the components of the electromagnet assembly 20 are sized so that the springs 160 urge the coil body 62 into engagement with the body portion 118 of the magnet pole and the body portion 118 into engagement with the shock pad 58 with clearance being provided between the surfaces 40 on the base 12 and the wall portion 72 on the molded body 62. Thus the springs 160 and the shock pad 58 absorb the shock accompanying the movement of the armature 54 to the d'e-energized position and thereby reduce the wear of the components of the electromagnetic device 10.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. In an electromagnetically operated device, the combination comprising: a base having a pair of supporting surfaces separated by a socket, a pair of spaced posts on the base presenting a pair of surfaces that face one another on opposite sides of the socket and free ends spaced from the supporting surfaces, each of said pair of facing surfaces on the posts having a slot therein extending in a common plane in the posts to the free ends of the posts, a magnet coil comprising a molded coil body having a side wall positioned on the pair of supporting surfaces and bridging the socket, a first end Wall positioned adjacent the pair of posts and overhanging the free ends of the posts, a pair of spaced bores extending parallel to one another between the first end and a second end of the coil body, and a coil winding surrounding one of the pair of bores, an E-shaped stationary magnet pole having the body portion positioned adjacent the first end of the coil body, a central leg extending from the body portion into the said one bore, a leg extending into a space provided by the socket and the side wall of the coil body, and a leg extending from the body portion into the bore other than the said one bore in the coil body, an E-shaped magnet armature having a body portion positioned adjacent the second end of the coil body, a first leg extending into the space provided by the socket and the side wall of the coil body, a second leg extending into the said other bore in the coil body, and a third leg extending into the said one bore in the coil body, and means including a plate having portions received in the slots providing a movable connection between the third leg of the armature and the base.

2. The combination as recited in claim 1 wherein resilient means carried by the base engages the second end of the coil resiliently maintains the first end wall of the coil against the pair of mounting posts.

3. The combination as recited in claim 1 wherein the coil includes a second side wall that extends remote from the base between the first and second end walls, said second side wall having an opening therein extending into a cavity in the coil body, including terminals having portions carried by the second side wall, portions connected to the coil winding and portions within the cavity, a lamp within the cavity connected to the portions of the terminals within the cavity so as to be illuminated upon energization of the coil, and a transparent cover closing the opening to the cavity whereby the illuminated lamp is visible when the coil is energized.

4. The combination as recited in claim 1 wherein the means providing the connection between the base and the armature includes a pair of arms extending from the third leg of the armature through the one bore and providing ends on the arms projecting beyond the body portion of the magnet pole, a notch in the projecting ends of the arms, and said plate having openings therein receiving the notches in the arms and edge portions positioned in the slots in the posts.

5. The combination recited in claim 4 wherein the plate is positioned adjacent the body portion of the magnet pole.

6. The combination as recited in claim 5 wherein a shock pad of polymeric material is positioned between the plate and the body portion of the magnet pole to absorb shock accompanying the movement of the armature in response to the energization and de-energization of the coil winding.

7. The combination as recited in claim 1 wherein the coil body is maintained in position on the base by a pair of screws passing through a pair of openings in the coil body and threaded into a pair of openings extending in the pair of posts from the free ends of the posts.

8. The combination as recited in claim 1 wherein a switch mechanism having a spring biased movable contact actuator is positioned on the base to have an actuating end portion of the movable contact actuator positioned adjacent the plate and the free ends of the arms are in engagement with the actuating end portion to move the movable contact actuator upon movement of the armature in response to the energization of the coil winding.

9. The combination as recited in claim 2 wherein the resilient means includes a pair of lead-like spring members each having a first end received in an opening in one of the support surfaces and a second end engaging the second end of the coil body.

10. In an electromagnetically operated device, the combination comprising: a base, a magnet coil comprising a molded coil body having a rear wall positioned on the base, a front wall disposed remote from the base to be visible when the base is mounted on a panel, a pairof end walls extending between the front and rear walls, a bore extending between the pair of end walls, a coil winding surrounding the bore, a cavity extending to an opening in the front wall, terminals carried by the coil body, said terminals having portions electrically connected to the coil winding and portions extending into the cavity, a lamp within the cavity connected to the portions of the terminals within the cavity so as to be illuminated when the coil winding is energized from a source connected to the terminals, and a transparent cover closing the opening in the front Wall whereby the illuminated lamp is visible when the device is mounted on a panel and the coil winding is energized.

References Cited UNITED STATES PATENTS 8/1966 Schubring 335-202 4/1969 Koertge 335-132 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,5 5,961 Dated August 25, 1970 I v Kenneth J Marien It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, line 17, "'electromgnetically" should read --e1ectromagnetically-.

Col. 2, line 48,, "compents" should read --components--; line 67, "srtuctureK should read --structure-- Col 3, lines 49 and .50, "adjacetn each occurrence should read --adJacent-; line 52, "illustraetd" should read --i1lustrated--,- line 57, provide" should read --provides--; line 62, "conections" should read --connections--.

Col 4, line 26, cancel "extending from a central portion of the body portion and insert --opposite ends of a body portion 118 with a central leg l20-; line 27, cancel "opposite ends of a body portion 118 with a central leg 120" a'nd insert -=-extending from a central portion of the body portion---; line 33, "154" should read -54--.

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